Improvement in nickel-plating



v TTNI TED STATES PATENT OFFICE.

ISAAC ADAMS, JR, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN NICKEL-PLATING.

Specification forming part of Letters Patent No. 136,634, dated March 11, 1873.

To all whom it may concern: 7

Be itknown that I, ISAAC AnAns, Jr., of Boston, in the county of Suffolk, iuthe State of Massachusetts, have invented a new and useful Improvement in the Electro-Deposition of Nickel, and in Electroplatin g with Nickel; and I-do hereby declare that the following is a full audexact description thereof:

In my patent, of August 3, 1869, I have given certain directions for the preparation and use of the double sulphate of nickel and ammonium, and thedouble chloride of nickel .and ammonium, by means of which the electro-deposition of nickel from the solutions could be effected with better results than had everbeen before obtained from them, and the art of electroplating with nickel could be successfully practiced.

I have found that the directions given in my said patent for preparing and using the above mentioned solutions are equally applicable to all the soluble salts of nickel, single or double, which are capable of being de composed by the electric current, such as the sulphate, the chloride, the tartrate, the bromide, the double tartrate of nickel and ammonia, the double bromide of nickel and ammonium, the succinate, &c., which, if prepared in such a manner as to be substantially free from the presence of potash, soda, alu- Inina, lime, and nitric acid, and free from acid and alkaline reaction, can be successfully used in the electro-deposition of nickel, or in electroplating with nickel. There is, however, a certain class of nickel salts, known as ammonia salts-e. 9., the ammonio-chloride, ammonio-bromide, ammonio-sulphate, ammo- -nio-tartrate, &c.of greater or less definite chemical composition, which are formed by dissolving the corresponding simple salts-e. 9., the chloride, bromide, sulphate, &c.-in a solution of ammonia, and which are of necessity alkaline.

Salts of this nature, when made and used in such a manner as to be free from the presence of potash, soda,lime, alumina, and nitric acid,

may be made to give, under the influence of a suitable current, a deposit of reguline metal, proper for the purpose of electroplating, and in amount sensibly proportionate to the current strength. There is, however, always a serious inconvenience attached to the use 0t such solutions, in that, owing to their alkalinity, they do not readily dissolve the anode. As a consequence of this, the plating solution, being but partially supplied from the anode, becomes gradually depleted of its metal, and in about the ratio of its alkalinity, so that the metallic salt must be frequently added in order to keep up the proper supply; the process thus ceases to be a continuous one, and is also attended with other disadvantages to the practical plater, viz: the increased expense attendant upon this manner of applying the solution with metal; the risk of introducing adventitious substances; the rapid accumulation of ammonia salts in the solution; the constant'change in the relative proportion of the materials of the bath, requiring corresponding changes in the strength and density of the current.

Each precaution and direction contained in said patent is founded upon independent discoveriesof the individual action and operation of the several substances and conditions named and while it is important, in order to produce the best results, to observe all the directions given, yet electroplaters may see fit to omit one or more of them, observing the rest; thus availing themselves of parts only of my discoveries. But it will be found that any departure from the directionsxgiven will be followed by a greater or less imperfection in the result. 5;.

On the 3d of August, 18 ters Patent for the electrop with nickel, or the electro-deposition of .j ckel, by means of a solution of the double sulphate of nickel and ammonia, and of a solutignof the double chloride of nickel and of amnio'rlijgm.

On the 22d of .March, 1870, I obtained Letters Patent for the electro-deposition of nickel or the electroplating with nickel by means of a solution of the double sulphate of nickel and magnesia; and on the 25th of May, 1870, I obtained Letters Patentifor the electrodeposition of nickel or the electroplating with nickel, by means of a solution of the double sulphite of nickel and ammonia; and referring to each of said Letters Patent for a more particular description of my said inventions, and disclaiming, in my present application, all

btained Letthatl have claimed in the Letters Patent soda, lime, al umin a-, and nitric acid, or either severally above mentioned, of them, and free from acid and alkaline re I. new claimaction, or from either. The electro-deposition of nickel, or the elec- ISAAC ADAMS, J 12.

rtoplating with nickel, by means of a solution of either of the soluble salts of nickel, such Witnesses:

solution being prepared and being used, sub- G. S. SGAMMON, 1 stantially, free from the presence of potash, JEROME '1. WHITE. 

